Cinematograph apparatus



sept. 1, 1959 vA. R. KUHNERT ETAL CINEMATOGRAPH APPARATUS Filed Sept. 26, 1955 United States Patent O CnsnMAroGRArH APPARATUS Alfred Rudolf Kuhnert and Bruno Johannes Rothe, Dresden, Germany, assignors to VEB Zeiss Ikon Dresden, Dresden, Germany Application September 26, 1955, Serial No. 536,607

2 Claims. (Cl. 88-17) The invention relates to an arrangement for the adjustment of the picture framing in cinematographic machines.

Narrow film projectors are known, -in which the picture framing adjustment is carried out by displacement of the optical axis., in that the objective or the objective carrier together with the mask of the picture iield disposed in the film gate is constructed of variable height, the film gate with the objective carrier forming a unit for the insertion of the iilm and for the cleaning of the iilm passage, the hlm gate `together with the objective carrier or a part of the objective carrier being movable in the direction of the optical axis.

This simple way of the adjustment of the picture framing in the case of high power machines, which operate with strong projection light source, atlords diiiculties in so far as the mask of the picture iield in these machines may not lie behind the ilm, seen in .the direction of projection, but must lie in front of the film in order to allow only the absolutely necessary light to fall on the ilm for the purpose of preventing excessive heating.

Now, in order to be able to use the above mentioned simple principle of the adjustment of the picture framing in such an arrangement of the mask of the picture iield in front of the iilm, it is proposed according to the invention to mount the mask of the picture field movably in the direction of the running of the lilm and to connect it fo-rm-lockingly by coupling elements with the iilm gate or with the part of the objective carrier movable in the direction of the optical axis in the case of closed iilm gate.

A preferable form of embodiment of the invention provides that the mask of the picture eld forms a part of the lm track and that the lm track is mounted movably in the direction of the running of the film.

Since in the oase of water-cooled film tracks it is ditlicult to eiect movements by the connections for the cooling liquid it is also proposed according to the invention to construct the mask of the picture iield as part of the ilm track insert, which is mounted movably in the direction of the running of the film on the lm track carrier, through which the cooling media iiows.

By means of the invention the use of the principle of the adjustment of the position of the picture by alteration of the optical axis requiring little expense is possible also in the case of high power machines, without extensive additional means being necessary.

One exempliiied embodiment of the invention is illustrated in the drawing, in which only the parts of a cinematograph projector necessary to an understanding of the invention are described.

`On a side wall P of a projector casing, a cylinder 1 is guided in a supporting bracket 2. The cylinder 1 is closed at the front by the lens mounting 3 and at the rear by the film gate 4, which carries presser means 5. In the cylinder 1 is formed a spiral groove 6 in which engages, in known manner, a guide bolt 7 which is fastened in an adjusting ring 8 guided on the bracket 2, so that when the knob 9 is operated the film gate can be opened and closed in the direction of the double arrow 10. The bracket 2 is mounted to be adjustable in the direction of the running of the lm (double 'arrow 14) by means of slotted guides 11 and `12., and guide bolts 22 and 23 fastened on the projector wall P. The adjustment is effected by turning the eccentric disc 13 by means of a handle (not shown). Opposite the iilm gate 4 is situated the iilm track carrier 15, which is provided with cavities 16 and 17 which are iilled with a cooling fluid. The iilm track insert 18, in which the frame mask 19 is disposed, is mounted to be slidable in the direction of running of the iilm (double arrow 14) on the film track carrier 15. A coupling element 20 is fastened on the lm gate 4 laterally outside the path of the film and, when the lm gate is closed, engages in the recess 21 in the iilm track insert, lso that on adjustment of the bracket 2 in the direction of the double arrow *14 the frame mask 19 is jointly adjusted to the same extent.

We claim:

l. An -arrangement for the adjustment of the picture raming on cinematographic machines comprising a wall constituting part of the housing of the machine, a bracket adjustably mounted 'on the wall for longitudinal movement in the direction of movement of the iih'n, said bracket having ya 'bore whose longitudinal [axis lies at right angles to the direction of movement of the ltn, a cylinder carried by `said bracket and slidable in the bore thereof so as to be adjustable relative to the bracket in the direction of the optical axis, a lens mounting carried by said cylinder, a lm gate also carried by said cylinder, a iihn .track carrier mounted on said wall, a iilm track insert adjustably mounted on the film track carrier having an aperture therethrough to form a ame mask which lies in front of the film from the projection direction, said film track insert being adjustable in the direction of the movement of the iilm through the lm gate, and coupling elements which are disposed on the ilm gate and on the tlm track insert respectively and which come into engagement with each other when the lm gate is closed and automatically disengage each other when the lm gate is opened.

2. An arrangement according to claim 1 in which the ilm track carrier has cavities through which a cooling medium flows.

References Cited in the iile of this patent UNITED STATES PATENTS 1,108,122 Blair Aug. 25, 1914 1,855,775 Shapiro Apr. 26, 1932 1,985,629 Crabtree Dec. 25, 1934 2,029,938 Newman Feb. 4, 1936 2,070,325 Victor Feb. 9, 1937 2,485,709 Davock Oct. 25, 1949 2,563,892 Waller et al. Aug. 14, 1951 2,617,327 DArcy Nov. 11, 1952 2,756,628 Lang July 31, 1956 2,775,161 Thevenaz Dec. 25, 1956 FOREIGN PATENTS 1,004,201 France Nov. 28, 1951 1,102,824 France May 11, 1955 

